/* 
 *  
 * uuid.js - Version 0.3 JavaScript Class to create a UUID like identifier 
 *  
 * Copyright (C) 2006-2008, Erik Giberti (AF-Design), All rights reserved. 
 *  
 * This program is free software; you can redistribute it and/or modify it under 
 * the terms of the GNU General Public License as published by the Free Software 
 * Foundation; either version 2 of the License, or (at your option) any later 
 * version. 
 *  
 * This program is distributed in the hope that it will be useful, but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 
 * details. 
 *  
 * You should have received a copy of the GNU General Public License along with 
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 
 * Place, Suite 330, Boston, MA 02111-1307 USA 
 *  
 * The latest version of this file can be downloaded from 
 * http://www.af-design.com/resources/javascript_uuid.php 
 *  
 * HISTORY: 6/5/06 - Initial Release 5/22/08 - Updated code to run faster, 
 * removed randrange(min,max) in favor of a simpler rand(max) function. Reduced 
 * overhead by using getTime() method of date class (suggestion by James Hall). 
 * 9/5/08 - Fixed a bug with rand(max) and additional efficiencies pointed out 
 * by Robert Kieffer http://broofa.com/ 
 *  
 * KNOWN ISSUES: - Still no way to get MAC address in JavaScript - Research into 
 * other versions of UUID show promising possibilities (more research needed) - 
 * Documentation needs improvement 
 *  
 */  
  
// On creation of a UUID object, set it's initial value  
function UUID() {  
    this.id = this.createUUID();  
}  
  
// When asked what this Object is, lie and return it's value  
UUID.prototype.valueOf = function() {  
    return this.id;  
}  
UUID.prototype.toString = function() {  
    return this.id;  
}  
  
//  
// INSTANCE SPECIFIC METHODS  
//  
  
UUID.prototype.createUUID = function() {  
    //  
    // Loose interpretation of the specification DCE 1.1: Remote Procedure Call  
    // described at  
    // http://www.opengroup.org/onlinepubs/009629399/apdxa.htm#tagtcjh_37  
    // since JavaScript doesn't allow access to internal systems, the last 48  
    // bits  
    // of the node section is made up using a series of random numbers (6 octets  
    // long).  
    //    
    var dg = new Date(1582, 10, 15, 0, 0, 0, 0);  
    var dc = new Date();  
    var t = dc.getTime() - dg.getTime();  
    var tl = UUID.getIntegerBits(t, 0, 31);  
    var tm = UUID.getIntegerBits(t, 32, 47);  
    var thv = UUID.getIntegerBits(t, 48, 59) + '1'; // version 1, security version is 2  
    var csar = UUID.getIntegerBits(UUID.rand(4095), 0, 7);  
    var csl = UUID.getIntegerBits(UUID.rand(4095), 0, 7);  
  
    // since detection of anything about the machine/browser is far to buggy,  
    // include some more random numbers here  
    // if NIC or an IP can be obtained reliably, that should be put in  
    // here instead.  
    var n = UUID.getIntegerBits(UUID.rand(8191), 0, 7)  
            + UUID.getIntegerBits(UUID.rand(8191), 8, 15)  
            + UUID.getIntegerBits(UUID.rand(8191), 0, 7)  
            + UUID.getIntegerBits(UUID.rand(8191), 8, 15)  
            + UUID.getIntegerBits(UUID.rand(8191), 0, 15); // this last number is two octets long  
    return tl + tm + thv + csar + csl + n;  
}  
  
//  
// GENERAL METHODS (Not instance specific)  
//  
  
// Pull out only certain bits from a very large integer, used to get the time  
// code information for the first part of a UUID. Will return zero's if there  
// aren't enough bits to shift where it needs to.  
UUID.getIntegerBits = function(val, start, end) {  
    var base16 = UUID.returnBase(val, 16);  
    var quadArray = new Array();  
    var quadString = '';  
    var i = 0;  
    for (i = 0; i < base16.length; i++) {  
        quadArray.push(base16.substring(i, i + 1));  
    }  
    for (i = Math.floor(start / 4); i <= Math.floor(end / 4); i++) {  
        if (!quadArray[i] || quadArray[i] == '')  
            quadString += '0';  
        else  
            quadString += quadArray[i];  
    }  
    return quadString;  
}  
  
// Replaced from the original function to leverage the built in methods in  
// JavaScript. Thanks to Robert Kieffer for pointing this one out  
UUID.returnBase = function(number, base) {  
    return (number).toString(base).toUpperCase();  
}  
  
// pick a random number within a range of numbers  
// int b rand(int a); where 0 <= b <= a  
UUID.rand = function(max) {  
    return Math.floor(Math.random() * (max + 1));  
}  
  
// end of UUID class file  